As telecommunications technology has evolved, more advanced network access equipment has been introduced that can provide services that were not possible previously. This network access equipment might include systems and devices that are improvements of the equivalent equipment in a traditional wireless telecommunications system. Such advanced network access equipment may be included in evolving wireless communications standards, such as long-term evolution (LTE), LTE Advanced (LTE-A), 5G, etc. For example, in an LTE system the advanced network access equipment might include an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) node B (eNB). In various wireless communications systems, the advanced network access equipment may include a base station, a wireless access point, or a similar component operable as an access node according to a corresponding wireless communications standard. Any such component will be referred to herein as an eNB, but it should be understood that such a component is not necessarily an eNB. Such a component may also be referred to herein as an access node or base station.
As used herein, the term “user equipment” (UE) can refer to mobile devices such as mobile telephones, personal digital assistants, handheld or laptop computers, and similar devices that have telecommunications capabilities. Such a UE might comprise a wireless device (also known as a Mobile Equipment (ME)) and its associated Universal Integrated Circuit Card (UICC) that includes a Subscriber Identity Module (SIM) application, a Universal Subscriber Identity Module (USIM) application, or a Removable User Identity Module (R-UIM) application or might comprise the device itself without such a card. The term “UE” may also refer to devices that have similar capabilities but that are not transportable, such as fixed line telephones, desktop computers, or set-top boxes. The term “UE” can also refer to any hardware, firmware, or software component that can terminate a Session Internet Protocol (SIP) session.
Services that might be provided by LTE-based equipment can include broadcasts or multicasts of television programs, streaming video, streaming audio, streaming data and other multimedia content. One such service is referred to as multimedia broadcast multicast services, which is specified by the Third Generation Partnership Project (3GPP) as MBMS. However, it is to be understood that as used herein, the term “MBMS” may refer more broadly to any suitable type of broadcast and/or multicast services (i.e., not necessarily to those specified by 3GPP). A broadcast or multicast service might be transmitted throughout a single cell or throughout several contiguous or overlapping cells. A set of cells receiving a broadcast or multicast service can be referred to as a service area. A service area and a region under the control of a central control entity do not necessarily coincide. For example, a central control entity might specify that a first subset of cells under its control will deliver a first MBMS and that a second subset of cells under its control will deliver a second MBMS.
When multiple cells overlap, a UE within the overlapped region can receive transmissions from multiple eNBs. Moreover, when a UE receives substantially identical data from a plurality of eNBs, the transmissions from the eNBs can augment one another to provide a signal of significantly higher quality than would be the case if only one eNB were transmitting the signal. That is, a higher signal-to-noise ratio can be achieved when substantially the same data is transmitted at substantially the same time on substantially the same resource with substantially the same modulation and coding. A region in which a plurality of substantially identical signals are present is known as a single frequency network, or SFN. In the case where all of the eNBs in a service area are transmitting an MBMS with substantially identical signals, the service area can be referred to as a multicast/broadcast single-frequency network (MBSFN).